Originally from Cleveland, Siebert moved to New York when she was 22 and found work as a stock analyst for Bache. She founded Muriel Siebert & Co. in 1966 and bought her NYSE seat in 1967.

"She affected pretty much all women because she was the first," says Susan Byrne, founder and chairman of Westwood Holdings, a money management firm with $19 billion under management. "And "Not only was she the first, but she welcomed all women."

Siebert's firm became a discount brokerage in 1975, when the Securities and Exchange Commission allowed brokerage commissions to be negotiated. "She was a great broker, loved her customers, and fought for the little guy," Byrne.

"Mickie Siebert was amazing to me, because, in some respects, she was like every other woman I have ever known - and in others - she was like no one else I have ever met. She was a trailblazer and a pathfinder, a leader and a friend," says Rep. Carolyn Maloney, D-NY.

Susan Byrne remembers Siebert as a generous friend and mentor. "She was always generous with her time," Byrne says. "She supported a lot of causes for women and children and education."

Siebert will be succeeded by Joseph M. Ramos, the company's chief operating officer. "This is obviously a great loss not only for our company but for the financial industry in general, "said Ramos in a statement. "Mickie was a pioneer and recognized as a leader throughout the industry and beyond.

Siebert took a leave of absence from the company in 1977 and placed it in a blind trust to be run by the employees when she was appointed the first woman superintendent of banking for the State of New York by Gov. Hugh Carey. She served five years.

As interest rates climbed steeply and bank failures became common, Siebert launched protective measures to prevent banks from failing in New York. She reorganized troubled banks, forced bank mergers, and convinced the federal government to advance millions of dollars to make the new mergers viable. She persuaded stronger institutions to help weaker ones.

In 1982, Siebert resigned from the job to run for the Republican nomination for the U.S. Senate seat of Daniel Patrick Moynihan. She came in second to a state lawmaker, Florence Sullivan, who went on to lose to Moynihan in the November election.

Siebert returned to running her company.

To celebrate 30 years as member of the exchange, Siebert was invited to ring the closing bell on the NYSE. The ceremony was held on Jan. 5, 1998.

The next year, while president of the New York Women's Agenda - a coalition of over 100 women's organizations - Siebert developed a personal finance program to improve the financial literacy of young people.

The program became part of the New York City high schools economics curriculum for seniors. Siebert worked to expand the program nationally.

An advocate for women in business, she served on several organizations including the Council on Foreign Relations, the International Women's Forum, Deloitte & Touche's Council for the Advancement and Retention of Women, and the New York Women's Forum, for which she was a founder and president.

Siebert also was a former appointee to the New York State Commission on Judicial Nomination and the National Women's Business Council.

"Muriel Siebert was a financial industry legend who took on Wall Street's then all-male establishment and proved to be an immense success," said Suzanne Shank, Co-Founder and President/CEO of Siebert Brandford Shank & Co., which she co-founded. "By her sheer tenacity and financial smarts, Mickie showed the world that women could be a success on Wall Street and in-turn opened doors and career opportunities for generations of women who today are leading some of the most important companies our economy depends upon. She was a dear friend and mentor to me and an inspiration to many more."

Siebert, who lived in New York City, never married and did not have any children.